Probably behind the glove box somewhere, but they aren't going to be sitting out in the open for you to change.

Your car is a W208 chassis. Scroll down to the W208 forum and look at the "stickies" (highlighted in blue at the top of the threads) to see if someone has already posted how you R&R the cabin filters. If not, ask there. That forum is designated for your chassis, and I'm sure somebody who is there can answer your question.

Good luck.

"Don't pick a fight with an old man. If he is too old to fight, he'll just kill you."--John Steinbeck